.pulse {
  animation-name: pulse;
  animation-duration: 1s;
  animation-iteration-count: infinite;
}
/* css性能优化 性能渲染交给GPU加速 动画不要影响周围的文档流 */
@keyframes pulse {
  from {
    transform: scale3d(1, 1, 1);
  }
  50% {
    transform: scale3d(1.5, 1.5, 1.5);
  }
  to {
    transform: scale3d(1, 1, 1);
  }
}
